Concealed-terminal receptacle.



H. C, ADAM.

CONCEALED TERMINAL RECEPTACLE.

AFPLICATION F lLED JULY 27.1917.

Patented Mar. 18, 1919.

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HARRY C. ADAM, OF ST. LOUIS, MISSOURI, ASSIGNOR TO THE REFLECTOLYTECOMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

CONCEALED-TERMINAL RECEPTACLE.

Specification of Letters Patent.

Patented Mar. 18, 1919.

minal Receptacles, of which the following is a full, clear, and exactdescription, such as will enable others skilled in the art to i which itappertains to make and use the same.

This invention relates to electrical receptacles of the type thatcomprise a onepiece insulator provided with concealed terminals.

The main object of my present invention is to provide an efficientelectrical receptacle of the type referred to which is so con structedthat the workman who installs same has easy access to the binding screwsof the terminals and can see said screws clearly during the operation ofconnecting the supply wires to the terminals, thereby tending to reducethe liabilityof producing a short circuit during the operation ofinstalling the electrical receptacle.

Figure l of the drawings is a side elevational view of a concealedelectrical receptacle constructed in accordance with my invention.

Fig. 2 is a vertical sectional view of same, taken on the line 22' ofFig. 1.

Fig. 3 is a bottom plan view of the receptacle; and

Fig. 4 is a detail horizontal sectional view taken on the line 4-4 ofFig. 1.

Referring to the drawings, which illustrate the preferred form of myinvention, A designates the insulator of the receptacle which consistsof a one-piece member formed of orcelain or other suitable insulatingmaterial and provided with a top portion 1 and a cylindrical portion 1that are integrally connected together. A screw-threaded shell 2 ofconventional form is arranged inside of the cylindrical portion 1 of theinsulator and is connected to the top portion. 1 of the same by means ofscrews, and the two terminals of the receptacle are arranged in openingsin the cylindrical portion 1 of the insulator in such a manner that theyare protected by the top portion 1 of the insulator, thus producing anelectrical receptacle that complies with all of the requirements of tireprevention oflicials as to the location of the terminals, but which hasthe distinguishinsulator.

ing and desirable characteristic of accessible binding screws that canbe clearly seen by the workmen during the operation of connecting thesupply wires to the terminals of the receptacle. In the form of myinvention herein shown the contact 3 of the receptacle is provided witha terminal 4 that is equipped with a binding screw 4?, and the contact 5is provided with a terminal 6 that is equipped with a binding screw 6*.Said terminals 4 and 6 are arranged diametrically opposite each other inopenings 7 formed in the side wall of the cylindrical portion 1 of theinsulator in proximity to the top portion 1 of the insulator. Ifdesired, each of said openings 7 can be provided with a lateral offset7, preferably formed by a groove in the outer surface of the cylindricalportion 1 of the insulator, so as to receive the supply wire at, asshown in Fig. 4, and thus permit the supply wires to be arrangedsubstantially tangential to the cylindrical portion 1 of the insulator.The top portion 1 of the insulator is enough larger than the cylindricalportion 1 to produce a, flange at the upper end of the insulator thatforms an adequate protection for the terminals. The terminals 4 and 6are also preferably arranged some distance inwardly from the outersurface of the cylindrical portion 1 of the insulator so that thebinding screws and the ends of the supply wires that are connected tothe terminals will be located within the marginal limits of thecylindrical portion 1 of the The top portion 1 of the insulator isprovided with two laterally-project ing ears arranged diametricallyopposite each other, as shown in Fig. 3, and each is provided with ahole 8* through which screws can be inserted. so as to secure theinsulator to a ceiling or other supporting structure arranged above theinsulator.

An electrical receptacle of the construction above described complieswith all of the requirements which fire prevention officials havedecided are essential for so-called concealed terminal'receptacles, andit also has a feature that none of the one-piece concealed terminalreceptacles now in general use possess. Namely, the terminals of sameand the binding screws on said terminals are clearly exposed to view,thus permitting the workman who installs the terminal to clearly seewhat he is doing when connecting the supply wires to the terminals, andconsequently, eliminating the possibility of producing shortcircuit, asso often occurs in connecting up concealed terminal receptacles of thekind now in eneral use.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is:

An electrical receptacle, comprising a, onepiece insulator provided witha cylindrical portion and a top portion integrally connected together,said top portion projecting laterally beyond said cylindrical portion soas to form a protecting flange, laterally projecting ears on said topportion through which screws or'connecting devices can e passed, thecylindrical portion of the insulator being provided in its sides justbelow said flange with openings that extend clear through same, contactscarried by said insulator and provided with terminals arranged in saidopenings in such a manner that the binding screws on the terminals willlie within the marginal limits of the cylindrical portion of theinsulator, and wire receiving grooves extending tangentially from saidopenings. 2

HARRY C. ADAM.

